PBS website Thirteen.org is reviving some great old TV content including what was the very first environmental documentary show.

"Vanishing Wilderness" bore some resemblance to the popular Mutual of Omaha's "Animal Kingdom" show (now available on the Animal Planet website), but it focused on particularly grave environmental disasters of the time — the Santa Barbara Oil Spill in 1969 (which started the modern environmental movement in the U.S. and led to the first Earth Day) and the Trans-Alaska pipeline.

There is also some cool nature footage like this clip of Owl vs. Snake. It's a far cry from the amazing new show "Life" on Discovery, but it's worth a visit.